1. Field of the invention
The present invention relates to vibration resistive instant responding roadway or bridge expansion joints and a construction method of the same, in particular, to a roadway or bridge expansion joint in which by means of movability of an expansion shim assembly in a sustaining pedestal to withstand vibration of the roadway or bridge and instantly rescue the roadway or bridge from collapsing. Moreover, a H configured clearance gauge is provided for determining clearances of adjacent component parts in constructing the expansion joint.
2. Description of the Prior Art
In selecting a well-suited expansion joint, in addition to effectiveness, other factors such as durability, economy, maintainability, and water drainage must also be taken into account.
Conventional roadway or bridge expansion joint, like one which was patented by Pat. No. 414820 in Taiwan is essentially a pre-buried elastic expansion joint element, this element restores its elastic property functionable as an expansion joint after the concrete dries which has been squeezing the element from the moment of pouring on. However, it has unsolvable problems of no way to expel water contained therein, and this expansion joint is only applicable for a short span roadway or bridge.
Another expansion joint disclosed by U.S. Pat. No. 382376 in Taiwan is essentially a sliding plate joint having an intricated structure which is susceptible to being filled with rubbish and loosing its effectiveness, on the other hand, its intricated structure gives rise of a high construction cost and difficulty in repairing. Besides, and expansion joint made of metallic material is inevitably corrosive.
Another well known conventional technology in the field of vibration resistive instant responding expansion joint is represented by so called xe2x80x9cFinger Plate Jointxe2x80x9d which is in the form of two piece of serrated steel plates. The serrated teeth of the two steel plates are staggeringly crossing one another so as to avoid squeezing each other when been stressed, and a drain ditch equipped beneath the expansion joint for draining water on the roadway or bridge surface. With this structure, the expansion joint is strongly constructed with steel plates formed with mutually staggered serration teeth to alleviate bouncing vibration imparted by heavy traffic, and at the same time, expel the water trickling down from the bridge or roadway surface. On the contrary, it has been reported that this expansion joint has disadvantages of high production cost, expensive repairing cost, and difficult to install.
In all, those aforementioned well known techniques about expansion joint have a common shortcoming of in complete vibration resistive property that the allowable clearance of the joint is insufficient to absorb the large verticall vibration deformational stress which might be caused by a severe earthquake resulting in catastrophic ruination of bridge and roadway and further leads to lives and property losses of human being.
Besides, in conventional techniques, some are want of assembly tools, while some are in need for special and complicated extra tools for assembly, both expensive labor cost and precious time are involved.
In view of the foregoing situation, the inventor of the invention herein conducted intensive research based on many years of experience gained through professional engagement in the manufacturing and construction of related products, with continuous experimentation and improvement culminating in the development of the improved structure for vibration resistive instant responding roadway or bridge expansion joint and construction method of the same herein.
It is an object of the present invention to provide a vibration resistive expansion joint having horizontally displaceable and turnable expansion shims which are replaceable one by one for defected shims, while the configuration of the shims can be changed according to specific requirements, moreover a proper clearance between two adjacent shims is reserved so as to cope with possible asymmetrical displacement of roadway or bridge surface separated by an expansion joint.
It is another object of the present invention to provide a vibration resistive expansion joint having stepped bench unit whose thickness and tilted angle is well-fitted to the grade of the roadway or bridge.
It is still another object of the present invention to provide a vibration resistive expansion joint equipped with a water receptacle beneath the expansion joint for releasing the water twickled down from the roadway or bridge surface.
It is one more object of the present invention to provide method for constructing an expansion joint having aforementioned effects.
For achieving these and other objects, the expansion joint of the present invention comprises a sustaining pedestal which is further formed of two sustasiming U shaped members, the top edge of each member is formed into a hinge bracket with a hinge hole, several expansion shim assemblies each formed of a bifurcated tooth like shim hinged to both side sustaining members are indented one antoher with those hinged at opposite member. Eash expansion shim assembly includes an independent tongue piece hinged to the sustaining member and is interposed in a gap of the bifurcated expansion shim and indented each other with opposite one. A hinge pin is used to connect each sustaining member with each expansion shim assembly. A foundation formed of two L shaped side members having a slide surface at each bottom surface thereof is provided with several fins at both outer side surfaces, and a guide rail is formed along each outer edge of the slide surface. A stepped bench unit formed of a pair of benches disposed at different elevation is slidably mounted on both side surfaces of the side foundation members. A water receptacle made of watertight material and having flanges along both side edges is inlaid in the both guide rails of the foundation to collect the water coming form the roadway or bridge surgace and trickling the water away thereform.
In the present invention, the sustaining pedestal, the stepped bench unit, and the foundation are engaged with screws at proper positions.
In the present invention, the contact edge of the respective expansion shim can be made into an arcuate shape or the like according to actual requirement.
In case it is considered necessary, the sustaining members can be reinforced with several reinforcement ribs.
As for the construction, a specially designed clearance gage is utilized for precisely determining clearance between two foundation members of expansion joint. The clearance gage is a supporting saddle with two parallelly erected plates at both sides. The construction steps are: Setting the clearance gage on the slide surfaces of the foundation to check the precise distance between the two foundation members, and then removing the clearance gage. Setting the bottom of the stepped bench unit on the slide surfaces. Setting the sustaining pedestal on the stepped bench unit. Connecting the expansion shim assemblies and the sustaining pedestal with both hinge pins and adjusting mutual positional relation. Engaging the sustaining pedestal, the stepped bench unit, and the foundation with tightening screws. Installing the water receptacle.